Current research continues to explore the nature of the prosocial behavior of helping another person by children under 3 years of age. Building on a baseline study of 2-year-olds helping their mothers and unfamiliar women execute some ordinary household tasks (in a specially designed laboratory setting), studies now include children at 18 and 30 months, with fathers as well as mothers as recipients, and male as well as female unfamiliar persons. Age changes in the amounts and kinds of participation are charted in both cross-sectional and longitudinal designs. Relationships are sought between how the adults signal and model the tasks and the children's helping, including also the effects of the adults' responses in maintaining the children's behavior. Upon completion of these studies, the prosocial behavior of caregiving (of dolls and toy animals in a nursery-like setting in the laboratory) is planned as the next topic of study. As with studies of helping, the behavior is first studied in 2-year-olds to provide baseline data. Together with earlier studies of sharing in this laboratory, the research should provide a full documentation of the very early development of these valued social achievements.